entropy
C1Substantiv/US /ˈɛntrəpiː/ ĔNTR-əp-ē; UK /ˈɛntrəpiː/ ĔNTR-əp-ē/
A certain property of a body, expressed as a measurable quantity, such that when there is no communication of heat the quantity remains constant, but when heat enters or leaves the body the quantity increases or diminishes.
